I bought a Colecovision off Craigslist, it came with a wire that plugs into a box w/ those two prongs like old tv antennas use. My tv doesn't have that plug in so I tried using both a Sega Genesis and an NES RF unit, but couldn't get anything out of the Sega Genesis and was finally able to get picture with the NES one. Unfortunately the picture is very static-y. Anyone know what I can do to improve the picture quality?